Gilbert: Tightening races raise prospect for split president, Senate result in Wisconsin

For much of 2024, polls suggested the Senate race and presidential race in Wisconsin were on slightly separate tracks, with the presidential contest a toss-up but Senate Democrat Tammy Baldwin holding a modest, steady edge over GOP challenger Eric Hovde.   

But in the latest Wisconsin survey by the Marquette Law School, these two races have both tightened.

In head-to-head matchups, Baldwin leads Hovde by 2 points for Senate and Vice President Kamala Harris leads former president Donald Trump by 1 point for president, according to Marquette's final pre-election poll of 753 likely voters in Wisconsin, taken Oct. 16-24.      

The closeness of both races leaves all sorts of possibilities open.

Either party could sweep Wisconsin's two top-of-the-ticket contests.

Or we could see a rare split outcome, with one party winning the Senate race and the other winning the presidential contest.  

The last time that happened in Wisconsin was 56 years ago in 1968.

But if both races are close enough, it wouldn't take too many Baldwin-Trump voters or Hovde-Harris voters to produce a split result.  

The relationship between the two races is further complicated by the expectation that there will be a bigger third-party vote for president than for Senate, meaning third-party presidential voters could play a role in the Baldwin-Hovde contest.

Harris does slightly better against Trump in Marquette's polling when independent candidates are included in the survey, such as Robert F. Kennedy Jr., who has withdrawn and endorsed Trump but remains on the Wisconsin ballot.

Meanwhile, Baldwin's very small lead over Hovde doesn't change when independents are included.

The tightness of the 2024 Senate race is a departure from Baldwin's first two elections, which she won by almost 6 points in 2012 and almost 11 in 2018.

The contest has narrowed as Baldwin's spending edge against Hovde has withered, the advertising wars have intensified, and GOP ads against Baldwin appear to have driven up her negatives.

In the new poll, 45% of voters viewed Baldwin favorably and 50% viewed her unfavorably. That is the highest unfavorable rating Baldwin has received in more than a decade of polling by Marquette, though her favorable rating is also higher than her long-term average.

Hovde's negatives are also at a high point this year, as the ad wars have boosted both candidate's negatives along with their overall name recognition. The GOP candidate is viewed favorably by 37% of voters and unfavorably by 48%.  

The closeness of the 2024 Senate race in this 50/50 state is in keeping with one very strong historical pattern.

When a Senate campaign coincides with a presidential campaign in Wisconsin, there is typically little separation between them, thanks to the polarizing effect of presidential elections.

The last time Wisconsin had a split outcome for president and Senate on the same ballot was when Republican Richard Nixon won the presidential contest here in 1968, and Democrat Gaylord Nelson won his Senate re-election bid.

Since then, these contests have been mostly in lockstep.

Democrats won both contests in 1976, Republicans won both in 1980, Democrats won both in 1988, 1992, 2000, 2004 and 2012; and Republicans won both in 2016.       

In most of these elections (2000 and 2004 were exceptions), the Senate and presidential contests were decided by similar margins (within 3 points of each other).  

The pattern is somewhat different in years when a Senate race coincides with a race for governor, with more ticket-splitting and more separation between the contests.   

For example, just two years ago, there was a split outcome for those two offices. Republican Ron Johnson won his 2022 Senate re-election bid by 1 point and Democrat Tony Evers won re-election as governor by more than 3 points.

In Baldwin's last race in 2018, the same party won both offices, but the difference in the margins reflected a relatively high amount of ticket-splitting for this day and age.  Evers won the governor's race by 1.1 points and Baldwin won the Senate race by almost 11.  

Craig Gilbertprovides Wisconsin political analysis as a fellow with Marquette University Law School's Lubar Center for Public Policy Research and Civic Education. Prior to the fellowship, Gilbert reported on politics for 35 years at the Journal Sentinel, the last 25 in its Washington Bureau. His column continues that independent reporting tradition and goes through the established Journal Sentinel editing process.
Follow him on Twitter: @Wisvoter .

This article originally appeared on Milwaukee Journal Sentinel: Could tightening races lead to a split result in Wisconsin